Quick ? I scoped up my 45 SBHH. Havent shot it yet, but was going to today. Then I got to thinking, I know, not always a good thing. But anyway, yesterday I loaded up a box of Hornady xtp's at .452. Then, out of curiosity decided to see if one would fit through the cylinder. Nope. So, I slugged the cylinder throats, and the bore. Bore at .4515, and the cylinders were between that and .4518. Now my question. Should I have the throats opened up before firing any of the Hornady's? To me it seems almost like a bore obstruction, although I'd be certain that somebody has shot some of these w/o even checking. Ultimately what I wanted to do was shoot a few hundred jacketed bullets to smooth things out and then convert over to cast. Your thoughts please.

Shoot them. There is no danger, and the accuracy will probably be fine.

Actually your bullet will expand a bit as it is pushed out of the brass. The purpose of the throat is to resize it to close the .452. Yours seem to be close enough to .452 to be ok. I have had Rugers in the past that had throats that were as much .002 small and not consistant sizes. I have a .452 reamer to correct it if it is off that much.

If not shooting cast I wouldn't worry about it. Shoot it first and see.

Should be fine until the cast. Then I would have them opened up to whatever bullet diameter you are going to be shooting.

I have a BH in 45 Colt and had my gunsmith look at it to "open" the throats.

0ne was .4515 and the rest were .452+ a tad.

I was fixated on the .4515 and ask him to open it up to 452.

He ask,

Problems with accuracy? I said no
Problems with Leading? I said, no

Then he said, it was fine and he would not touch it.

Still fine

Snake

Thanks for your thoughts. I was going to shoot today but it wasn't in the cards. Maybe by Sunday. Thanks fellas.

Throats should be groove size or a tad over. Even a few ten thousands over groove is OK and your gun should also shoot cast.
Only throats under groove are a problem and there is no sense in having too large of throats either.
You just might have perfection as the gun is and all you need do with cast is to size to fit the throats.
I would say you have a winner there.

I would not worry about the throats even shooting cast the t=hroats are larger than the bore without being excessivve

No problem at all

Agreed. But, what I was refering to is that if not shooting cast I wouldn't worry about it at all. Cast requires attention to details that jacketed does not, which is one reason I avoid it.

If the throats are too large they allow the bullet to wobble getting out of alignment affecting accuracy. With a cast bullet one can cast a larger diameter bullet that fits the throats and allow the forcing cone and barrel to swage the bullet down and accuracy improves greatly. No ability to do this with a mass produced jacketed bullet. The cast bullet is more versatile IME